RU2320044C2 - Surge discharger active part - Google Patents

Abstract

FIELD: surge dischargers.

SUBSTANCE: proposed surge discharger active part has two connectors disposed along axis and spaced apart through certain distance, at least one cylindrical varistor column disposed between two connectors, and at least one insulating frame supported by both connectors thereby affording integral active part to build up contact pressure. Novelty is that at least one of connectors has electrode disposed perpendicular to axis z and made in the form of plate, as well as electric junction member built integral with mentioned plate. In addition, there are supporting means in the form of projections for insulating frame which are provided in plate and/or on plate edge (built integral with plate).

EFFECT: reduced height of active part and material input for device manufacture.

12 cl, 9 dwg

Description

FIELD OF THE INVENTION

The invention relates to the active part of the arrester for surge protection, described in the restrictive part of claim 1 of the claims. The invention also relates to a surge arrester, which includes this active part.

The active part includes two connectors that are located along the axis at a certain distance from each other and to which a voltage in the range of more than 1 kV can be applied. Between these two connectors is a varistor column, which can be formed either from one varistor element or from two or more series-connected varistor elements. The active portion also comprises a dielectric frame or, possibly, two or more dielectric frames. This frame rests on both connectors, thus holding these connectors and the varistor column together and thus creating a contact force. The frame can rest on one of the two connectors and on the fastener located between the two connectors in the varistor column, and can hold together the part of the varistor column, which is limited by the support connector, and said fastener, thereby creating a contact force.

The surge arrester is designed to protect the active part from direct contact or dirt, for example, by enclosing it in a polymer or by installing it in a casing, possibly gas-insulated.

State of the art

As indicated in the characterizing part of the independent claim, this invention relates to the field of surge arresters, such as those disclosed in EP 614198 B1 or US Pat. No. 5,942,968. Each of the surge protectors described in these patent publications includes the active part, which is made in the form of a varistor column and enclosed in a polymer casing, in which the varistor column is held between two connectors. A holding force, which at the same time is also a contact force in the active part, is applied by means of one or more prestressed dielectric frames, which are supported by both connectors. Each of the connectors is machined from a metal cylinder and has grooves and / or protrusions, each of which is used to hold one end of the dielectric frames. In addition, the connectors have openings in the direction of the column to accommodate electrical connecting elements, and possibly also a cavity, which also extends in the direction of the column and is used to accommodate part of the varistor column. Therefore, the connectors extend over a relatively large distance in the direction of the column and thereby increase the physical height of the active part, and hence the surge arrester itself, to protect against overvoltages.

It should also be noted that the document EP 1066640 B1 describes a surge arrester having an active part that contains a varistor column, and in this case, a fastener having support points on which prestressed dielectric frames extending from top to bottom connector of the active part. These dielectric frames are also used to create holding and contact forces. The fastener provides a dielectric loading of the active part to a greater extent than in the aforementioned known technical solutions, which leads to a surge arrester, which belongs to the class of higher voltages.

SUMMARY OF THE INVENTION

The invention described in the claims provides a solution to the problem of creating an active part of the type that is mentioned at the beginning of the description, but differs in small physical height.

In the case of the active part according to the invention, at least one of the two connectors has an electrode that is perpendicular to the axis and made in the form of a plate, as well as an electrical connecting element, which is made on the plate as a unit with it, and means for supporting one end of the dielectric frame, which are made in the plate and / or made on the edge of the plate as a whole with it. Thus, on the one hand, the physical height of the active part is significantly reduced. On the other hand, connectors can now be manufactured using less material and less labor, thereby significantly reducing production costs for the active part.

To save material, it is recommended to make a flat electrical connecting element, which runs as a unit with the plate. Such an electrical connecting element can be connected to the plate at any desired angle relative to the plane of the plate, depending on the layout and configuration of the conductor to be connected to this plate. To ensure ease of connection of the conductor, it is preferable to make the electrical connecting element in the form of a perforated plate or plug contact.

In one specific embodiment of the active part, the contact force is generated by at least one plate spring, this spring can be centered to maintain a predetermined physical height by an axial symmetrical centering boss, which protrudes from the surface of the plate facing the varistor column. This boss can be made on the plate, but can be made in the form of an insertion part and can be fixed in a recess in the plate. The boss passes through an opening in a Belleville spring, which is generally made in the form of a conical annular disk. In order to prevent the cup spring from being stretched excessively during installation or during operation of the active part, the diameter of the centering boss and the inner diameter of the ring disk must be consistent with each other, preventing the cup spring from being flattened.

In the case of the active part according to the invention, the support means advantageously have at least one protrusion, which is made on the edge of the plate as a unit with it and is narrower than the diameter of the varistor column. A narrow protrusion is preferred, in particular for the manufacture of active parts with large diameters. Two or more of such narrow protrusions and the corresponding number of dielectric frames make it possible to produce a mechanically strong active part while maintaining a low physical height, which is also determined by the thickness of the plate.

If the supporting means have a protrusion that is made in the plate and passes through the axis of the varistor column, then it is possible to achieve mechanical strength and the desired contact force of the active part while maintaining a low physical height and using a single dielectric frame. The mechanical strength is further increased by supporting means, which have two protrusions, each of which is made on one of two sections of the plate edge, which runs in a straight line. Regardless, only one, two, or possibly even more protrusions are provided on the plate to provide acceptable mechanical strength and uniform contact pressure while maintaining a low physical height, it is preferable that each protrusion has a surface that is substantially parallel to the surface of the plate over most of the length of the plate, and that the corresponding frame was made in the form of a rectangle and supported from the inside by means of one of the rectangular faces to the surface.

Brief Description of the Drawings

The following is an explanation of the invention with reference to the accompanying drawings, in which:

figure 1 depicts a first specific embodiment of the active part in accordance with the invention;

figure 2 is a first specific embodiment of the active part, front view;

figure 3 is a first specific embodiment of the active part, side view;

figure 4 - a specific embodiment of a surge arrester for surge protection, which is intended for indoor use and includes the active part shown in figures 1-3;

5 is a specific embodiment of a surge arrester, which is intended for outdoor use and includes the active part shown in FIGS. 1-3;

6 is a second specific embodiment of the active part in accordance with the invention, which is designed for high dielectric load;

Fig.7 is a third specific embodiment of the active part in accordance with the invention in plug-in design;

Fig. 8 is a fourth specific embodiment of an active part in accordance with the invention; and

Fig.9 is a fifth specific embodiment of the active part in accordance with the invention.

Preferred Embodiments

The same positions in all the drawings indicate the same elements. The active part, which is shown in figures 1-3, has two connectors 10, 20, which are made of electrically conductive material, such as aluminum, and are spaced from each other along the z axis (figure 1). Each of the connectors 10 and 20 has an electrode that is perpendicular to the axis and made in the form of a plate 11 or 21, respectively, as well as a corresponding electrical connecting element 12 or 22, which is made on the corresponding plate 11 or 21 as a whole with it. On sections of the edge of the plates that extend in a straight line, protrusions 13, 14 and 23, 24 are made on opposite faces of the plates. The boss 15 or 25, respectively, which is in the form of a disk, protrudes respectively from the lower edge of the plate 11 or from the upper face of the plate 21 This boss 15 or 25, respectively, surrounds the z axis with respect to rotation symmetry and is used to center and guide one or more disk springs 16 or 26, each of which is made in the form of a conical ring disk and consists of an electrically conductive m the material.

The corresponding boss 15 or 25, the corresponding disk spring 16 or 26 and the cylindrical varistor column (30) made of a material with a non-linear characteristic of resistivity, for example, based on a metal oxide, in particular, such as ZnO, are located coaxially between the connectors 10, 20. As you can see, the varistor column 30 is made of a single varistor element, but may also include two or more elements stacked one on top of the other. The upper or lower end surface of the varistor column 30, respectively, comes into contact with the current contact element 17 or 27, respectively. Between the corresponding plate spring 1 b or 26 and the current contact element 17 or 27, respectively, an electrically conductive spring 18 or 28 is provided, which absorbs pressure.

As can be seen from figure 2 and 3, the active part is made in the form of a column. The column base is formed by a plate 21, and the head is formed by a plate 11. As shown in FIG. 1, a disk spring 26, a plate 28, a shock absorbing pressure, a current contact element 27, a varistor column 30, a current contact element 17, a plate 18 are arranged in series. shock-absorbing pressure, and a Belleville spring 16. Thus, the column is held together with the above elements through two rectangular dielectric frames 41 and 42. The column is pre-stressed by the force of the Belleville springs N 16, 26 during the manufacture of the active part. In the manufacturing process, the Belleville springs are centered on two bosses 15 and 25. The diameters of the centering bosses 15 and 25, respectively, and the diameters of the Belleville springs 16 and 26, respectively, made in the form of ring disks, correspond to each other to prevent flattening of the Belleville springs, and hence to prevent associated with this unacceptable excessive stretching. When the column is pre-stressed, the dielectric frames 41 and 42 are respectively put on the corresponding protrusions 13, 23 and 14, 24, and then the column is de-energized. The movement of the springs, characteristic of Belleville springs, is provided such that the force that is applied by them and absorbed by the dielectric frames is sufficient to hold the column together with the entire active part. Since the active part has to temporarily conduct current under certain operating conditions, the force is chosen large enough to keep the contact resistances small in the path of the current flowing from the connector 10 through the varistor column 30 to the connector 20.

As can be seen from figure 3, the protrusions 13, 23 have a surface that is mainly parallel to the surface of the plate along the main length of the plate, and the rectangular dielectric frame 41 is supported from the inside by two mutually opposite faces on these surfaces. This configuration of the protrusions and the dielectric frame allows the dimensions of the connectors 10, 20 to be kept small and reduced to the thickness of the plates 11 or 21. In addition to the small physical height of the active part, this also guarantees its mechanical strength and its conductive ability.

To reduce the consumption of materials and production costs, the electrical connecting elements 12, 22 are made flat. In practice, they can be made at any desired angle on the plates 11, 22 as a unit with them. If these connecting elements are oriented in the direction of the z axis, are centered on the plates as a unit with them and in the form of a perforated plate, as shown in a possible specific embodiment, shown in Figs. 1-3, then even a heavy cable conductor onto which high voltage can be applied, can be screwed to the connecting element 12, and the corresponding grounding conductor can be screwed to the connecting element 22, thereby saving space. Alternatively, as shown in Fig.7, the connecting elements 12, 22 can be oriented in the direction of the plates 11, 21 and can be made, for example, in the form of plug connections.

As can be seen from FIGS. 4 and 5, the varistor column, connector plates, and dielectric frames may be surrounded by an insulating material, for example, a polymer based on silicone or epoxy. Depending on the purpose of the surrounding dielectric compound, this leads to a surge arrester, which is suitable for indoor or outdoor use (Fig. 4) or Fig. 5 and has electrical connecting elements 12, 22 that exit from the dielectric casing fifty.

Dielectric frames do not have to rely on both connectors. As can be seen from the specific embodiment of FIG. 6, a metal fastener 31 may be located in the varistor column in the active part, which may be under high voltage. Then, the dielectric frames 41, 42 are supported on the upper plate 11 of the connector 10 and on the fastener 31, which provides supporting and contact force on the upper portion of the active part. A dielectric frame 43 and another dielectric frame, which is not visible in the drawing, are supported on the fastener 31 and on the plate 32 of the lower connector 20, and these frames create a supporting and contact force on the lower portion of the active part.

In the specific embodiment of the active part shown in Fig. 9, only two protrusions 200 and 201 are provided as supporting means, formed in the plates 11, 21 and passing through the z axis of the varistor column. This ensures that the dielectric frame 40, which is also made in the form of a rectangle, is held centrally in the region of the z axis, and also guarantees uniform holding and contact force in the active part. This provides a uniform current density for the dissipation current that travels along the active part when overvoltage occurs.

As shown in FIG. 8, protrusions 131, 132, 231, 232 can be formed at the edges of the plates 11, 21 as support means, and these protrusions are narrower than the diameter of the varistor column. Without prejudice to the advantage of a low physical height and material saving, it is possible to provide the necessary holding and contact force in the active part by means of a relatively large number of narrow dielectric frames 411, 412.

Claims (12)

1. The active part of the surge arrester, containing two connectors (10, 20) located along the axis (z) at a distance from each other, at least one cylindrical varistor column (30) located between two connectors (10, 20), and at least one dielectric frame (40, 41, 42, 43, 411, 412), which rests either on both connectors (10, 20), or on one of two connectors (10, 20), and a fastener (31) located between the two connectors (10, 20) in the varistor column (30), and holds together the varistor column (30) or part a varistor column (30), which is limited by a support connector (10, 20), and said fastener (31), thereby creating a contact force, characterized in that at least one of the two connectors (10, 20) has an electrode which is located perpendicular to the axis (z) and is made in the form of a plate (11, 21), as well as an electrical connecting element (12, 22), which is made on the plate (11, 21) as a unit with it, and means for supporting one end of the dielectric frame (40, 41, 42, 43, 411, 412), which are made in the plate (11, 21) and / or made on ayu plates (11, 21) as a whole with her. 2. The active part according to claim 1, characterized in that the electrical connecting element (12, 22) is flat. 3. The active part according to claim 2, characterized in that the electrical connecting element (12, 22) is made in the form of a perforated plate or a plug contact. 4. The active part according to one of claims 1 to 3, characterized in that from the surface of the plate (11, 21) facing the varistor column (30), a centering boss (15, 25) symmetrical with respect to the axis protrudes, used for direction, at least one disk spring (16, 26), which is made in the form of a conical annular disk. 5. The active part according to claim 4, characterized in that the diameter of the centering boss (15, 25) and the inner diameter of the annular disk correspond to each other in order to prevent the cup spring from flattening (16, 26). 6. The active part according to one of claims 1 to 3, characterized in that the support means include at least one protrusion (131, 132, 231, 232), which is made on the edge of the plate (11, 21) as a whole with it is narrower than the diameter of the varistor column (30). 7. The active part according to one of claims 1 to 3, characterized in that the support means include a protrusion (200, 201), which is made in the plate (11, 21) and passes through the axis (z) of the varistor column (30). 8. The active part according to one of claims 1 to 3, characterized in that the support means include protrusions (13, 14, 23, 24), which are made in the plate (11, 21), each of which is located in one of two sections the edges of the plate (11, 21), which runs along a straight line. 9. The active part according to claim 7, characterized in that the protrusion has a surface that is essentially parallel to the surface of the plate along the main length of the plate, while the frame (40, 41, 42, 43) is made in the form of a rectangle and is supported from the inside by one of rectangular faces on the specified surface. 10. Surge arrestor according to claim 8, characterized in that the protrusion has a surface that is substantially parallel to the surface of the plate along the main extent of the plate, while the frame (40, 41, 42, 43) is made in the shape of a rectangle and is supported from the inside by means of one of the rectangular faces on the specified surface. 11. Surge arrester, characterized in that it includes an active part according to any one of claims 1 to 3, as well as a casing (50), which is made of insulating material and surrounds the varistor column (30), parts of the connectors (10, 20 ) and a dielectric frame (40, 41, 42, 43). 12. Surge arrester according to claim 11, characterized in that the electrical connecting elements (12, 22) of the connectors (10, 20) come out of the casing (50).

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